SYSTEMS AND METHODS FOR POINT DEFECT COMPENSATION
20220358867 · 2022-11-10
Inventors
- Hari P. Paudel (Milpitas, CA, US)
- Chaohao Wang (Sunnyvale, CA, US)
- Hopil Bae (Palo Alto, CA, US)
- Mahdi Farrokh Baroughi (Santa Clara, CA, US)
- Wei Chen (Palo Alto, CA, US)
- Wei H. Yao (Palo Alto, CA)
Cpc classification
G09G2320/0271
PHYSICS
G09G2320/0233
PHYSICS
G09G2320/0242
PHYSICS
G09G3/20
PHYSICS
International classification
G09G3/20
PHYSICS
Abstract
An electronic device may display image content via an electronic display by controlling light emission from display pixels of the electronic display. A processor of the electronic device may receive image data destined for a defective display pixel (e.g., dim pixel, dead pixel). The processor may convert a gray level of the image data into a luminance domain to generate a target luminance that would have been emitted by the defective display pixel had the display pixel not been defective. After selecting a compensation mask, the processor may distribute the target luminance of the defective display pixels to nearby non-defective pixels of the electronic display to conceal the presence of the defective display pixel.
Claims
1. An electronic device comprising: an electronic display comprising a plurality of display pixels configured to display image content; and image processing circuitry configured to: receive image data destined for a defective display pixel from the plurality of display pixels; convert a gray level of the image data into a luminance domain to generate a target luminance that would have been emitted by the defective display pixel; and distribute the target luminance of the defective display pixel to a nearby plurality of non-defective display pixels of the electronic display within a distance of the defective display pixel according to a compensation mask.
2. The electronic device of claim 1, wherein distributing the target luminance comprises adding or subtracting a portion of the target luminance to the nearby plurality of non-defective display pixels.
3. The electronic device of claim 1, wherein the compensation mask is selected based on respective locations associated with the defective display pixel and the nearby plurality of non-defective display pixels of the electronic display.
4. The electronic device of claim 3, wherein the image processing circuitry is configured to: identify one or more angular features of the image content; and select the compensation mask according to the one or more angular features and the respective locations associated with the defective display pixel and the nearby plurality of non-defective display pixels.
5. The electronic device of claim 4, wherein the one or more angular features comprise a honeycomb pattern, a horizontal pattern, a vertical pattern, a 45° diagonal pattern, a −45° diagonal pattern or any combination thereof.
6. The electronic device of claim 4, wherein the compensation mask is selected based on a pixel arrangement associated with the electronic display.
7. The electronic device of claim 6, wherein the pixel arrangement associated with the electronic display comprises a hexagonal grid, a square grid, a rectangular grid, or any combination thereof.
8. The electronic device of claim 7, wherein when the pixel arrangement associated with the electronic display comprises the hexagonal grid, the image processing circuitry is configured to select the compensation mask without identifying the one or more angular features of the image content.
9. The electronic device of claim 1, wherein the electronic display comprises a self-emissive display.
10. The electronic device of claim 1, wherein the image processing circuitry is configured to convert the luminance domain of a nearby non-defective display pixel of the nearby plurality of non-defective display pixels to the gray level after distributing a portion of the target luminance to the nearby non-defective display pixel of the nearby plurality of non-defective display pixels.
11. A system, comprising: a display panel comprising a plurality of display pixels; processing circuitry configured to generate image data to be displayed on the display panel; and image compensation circuitry configured to: receive the image data associated with a total luminance; receive an indication of a defective display pixel from the plurality of display pixels based on the image data; convert a gray level of the image data into a luminance domain to generate a target luminance that would have been emitted by the defective display pixel; deactivate the defective display pixel such that the defective display pixel is fully dark; and distribute the target luminance of the defective display pixel to a nearby plurality of non-defective display pixels of the display panel within a distance of the defective display pixel according to a point spread function.
12. The system of claim 11, wherein the image compensation circuitry is configured to distribute the target luminance by adding or subtracting a portion of the target luminance to the nearby plurality of non-defective display pixels without changing the total luminance of the image data.
13. The system of claim 11, the image compensation circuitry is configured to distribute the target luminance according to the point spread function based on respective locations of the defective display pixel and the nearby plurality of non-defective display pixels of the display panel, a pixel arrangement associated with the display panel, or both.
14. The system of claim 13, wherein the pixel arrangement associated with the display panel comprises a hexagonal grid or a square grid.
15. The system of claim 14, wherein when the pixel arrangement associated with the display panel comprises the square grid, the image compensation circuitry is configured to distribute the target luminance according to the point spread function based on identifying one or more angular features of the image data.
16. The system of claim 15, wherein the one or more angular features comprise honeycomb pattern, a horizontal pattern, a vertical pattern, a 45° diagonal pattern, a −45° diagonal pattern or any combination thereof.
17. The system of claim 11, wherein the image compensation circuitry is configured to distribute the target luminance of the defective display pixel to the nearby plurality of non-defective display pixels of the display panel such that a visibility error associated with the defective display pixel is within a threshold visibility error.
18. The system of claim 11, wherein the point spread function comprises a 2D point spread function.
19. A method, comprising: receiving, via one or more processors, image data destined for a defective display pixel from a plurality of display pixels of an electronic display; converting, via the one or more processors, a gray level of the image data into a luminance domain to generate a target luminance that would have been emitted by the defective display pixel; and selecting, via the one or more processors, a compensation mask to distribute the target luminance to a nearby plurality of non-defective display pixels, such that a magnitude of a portion of the target luminance added to or subtracted from a respective luminance of a nearby non-defective display pixel of the nearby plurality of non-defective pixels decreases as a distance of the nearby non-defective display pixel relative to the defective display pixel increases.
20. The method of claim 19, wherein the electronic display comprises a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a liquid crystal display (LCD), a digital micromirror device (DMD) display, or any combination thereof.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:
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DETAILED DESCRIPTION
[0026] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions are made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0027] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, the phrase A “based on” B is intended to mean that A is at least partially based on B. Moreover, the term “or” is intended to be inclusive (e.g., logical OR) and not exclusive (e.g., logical XOR). In other words, the phrase A “or” B is intended to mean A, B, or both A and B.
[0028] With the preceding in mind and to help illustrate, an electronic device 10 including an electronic display 12 is shown in
[0029] The electronic display 12 may be any suitable electronic display. For example, the electronic display 12 may include a self-emissive pixel array having an array of one or more of self-emissive display pixels. The electronic display 12 may include any suitable circuitry to drive the self-emissive display pixels, including for example row driver or column drivers (e.g., display drivers). The self-emissive display pixels may include any suitable light emitting element, such as an LED, one example of which is an OLED. However, any other suitable type of display pixel, including non-self-emissive display pixels (e.g., liquid crystal as used in liquid crystal displays (LCDs), digital micromirror devices (DMD) used in DMD displays) may also be used.
[0030] The electronic device 10 includes the electronic display 12, one or more input devices 14, one or more input/output (I/O) ports 16, a processor core complex 18 having one or more processor(s) or processor cores, local memory 20, a main memory storage device 22, a network interface 24, and a power source 26 (e.g., power supply). The various components described in
[0031] In some embodiments, the processor core complex 18 may include imaging processing circuitry to process image data based at least in part on compensation parameters (e.g., compensation mask) before processed pixel data is used to display corresponding image content on the electronic display 12. To compensate for defective display pixels (e.g., partially or fully dark display pixels), the image processing circuitry may process pixel data based on a compensation mask.
[0032] The processor core complex 18 is operably coupled with local memory 20 and the main memory storage device 22. Thus, the processor core complex 18 may execute instruction stored in local memory 20 or the main memory storage device 22 to perform operations, such as generating or transmitting image data. As such, the processor core complex 18 may include one or more general purpose microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable logic arrays (FPGAs), or any combination thereof.
[0033] In addition to instructions, the local memory 20 or the main memory storage device 22 may store data to be processed by the processor core complex 18. Thus, the local memory 20 and/or the main memory storage device 22 may include one or more tangible, non-transitory, computer-readable media. For example, the local memory 20 may include random access memory (RAM) and the main memory storage device 22 may include read-only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, or the like.
[0034] The network interface 24 may communicate data with another electronic device or a network. For example, the network interface 24 (e.g., a radio frequency system) may enable the electronic device 10 to communicatively couple to a personal area network (PAN), such as a Bluetooth network, a local area network (LAN), such as an 802.11x Wi-Fi network, or a wide area network (WAN), such as a 4G, Long-Term Evolution (LTE), or 5G cellular network. The power source 26 may provide electrical power to one or more components in the electronic device 10, such as the processor core complex 18 or the electronic display 12. Thus, the power source 26 may include any suitable source of energy, such as a rechargeable lithium polymer (Li-poly) battery or an alternating current (AC) power converter. The I/O ports 16 may enable the electronic device 10 to interface with other electronic devices. For example, when a portable storage device is connected, the I/O port 16 may enable the processor core complex 18 to communicate data with the portable storage device. The input devices 14 may enable user interaction with the electronic device 10, for example, by receiving user inputs via a button, a keyboard, a mouse, a trackpad, or the like. The input device 14 may include touch-sensing components in the electronic display 12. The touch sensing components may receive user inputs by detecting occurrence or position of an object touching the surface of the electronic display 12.
[0035] In addition to enabling user inputs, the electronic display 12 may include a display panel with one or more display pixels. The electronic display 12 may control light emission from the display pixels to present visual representations of information, such as a graphical user interface (GUI) of an operating system, an application interface, a still image, or video content, by displaying frames of image data. To display images, the electronic display 12 may include display pixels implemented on the display panel. In some embodiments, the display pixels may represent sub-pixels that each control a luminance of one color component (e.g., red, green, or blue for an RGB pixel arrangement or red, green, blue, or white for an RGBW arrangement).
[0036] The electronic display 12 may display an image by controlling light emission from its display pixels based on pixel or image data associated with corresponding image pixels (e.g., points) in the image. In some embodiments, pixel or image data may be generated by an image source, such as the processor core complex 18, a graphics processing unit (GPU), or an image sensor. Additionally, in some embodiments, image or pixel data may be received from another electronic device 10, for example, via the network interface 24 and/or an I/O port 16. Similarly, the electronic display 12 may display frames based on pixel or image data generated by the processor core complex 18, or the electronic display 12 may display frames based on pixel or image data received via the network interface 24, an input device, or an I/O port 16.
[0037] The electronic device 10 may be any suitable electronic device. To help illustrate, an example of the electronic device 10, a handheld device 10A, is shown in
[0038] The handheld device 10A includes an enclosure 30 (e.g., housing). The enclosure 30 may protect interior components from physical damage or shield them from electromagnetic interference, such as by surrounding the electronic display 12. The electronic display 12 may display a graphical user interface (GUI) 32 having an array of icons. When an icon 34 is selected either by an input device 14 or a touch-sensing component of the electronic display 12, an application program may launch.
[0039] The input devices 14 may be accessed through openings in the enclosure 30. The input devices 14 may enable a user to interact with the handheld device 10A. For example, the input devices 14 may enable the user to activate or deactivate the handheld device 10A, navigate a user interface to a home screen, navigate a user interface to a user-configurable application screen, activate a voice-recognition feature, provide volume control, or toggle between vibrate and ring modes.
[0040] Another example of a suitable electronic device 10, specifically a tablet device 10B, is shown in
[0041] With the foregoing in mind,
[0042] Since attempting to display image data using a defective display pixel 50 may result in image artifacts, the defective display pixel 50 may be deactivated (e.g., turned off, bypassed, programmed with gray level 0). The image data that would have been programmed into the defective display pixel may instead be distributed to nearby non-defective display pixels 48 in a way that at least partially conceals the defective display pixel 50. After applying the compensation mask (e.g., compensation masks 53, 56) to pixel data based on respective locations of the defective display pixel 50 and the non-defective display pixels 48, a particular pixel arrangement of the electronic display 12, or both, a defective display pixel 50 may appear to be less visible on the electronic display 12. For example, after compensating for a point defect, a dead display pixel 50 (e.g., fully dark display pixel) may appear as a brighter display pixel rather than a fully dark display pixel on the electronic display 12. As illustrated in
[0043] As used herein, if the electronic display 12 was arranged as the square grid 52, the compensation mask 53 may be used to conceal the defective display pixel 50 by offsetting nearby non-defective display pixels 48 (e.g., including non-defective pixels 40, 42) with a portion of a target luminance, which is a luminance emitted by the defective display pixel 50 had it not been defective. Offsetting involves adding or subtracting a portion of the target luminance to the nearby non-defective display pixels. In some embodiments, the target luminance may be distributed to nearby non-defective display pixels 48 according to a point spread function (e.g., 2D point spread function). The point spread function may involve the distribution of luminance to surrounding display pixels relative to the defective display pixel 50. For example, to compensate for a fully dark display pixel 50, the image processing circuitry may add a portion of the target luminance to the non-defective display pixels 40 immediately adjacent to the defective display 50 with respect to the square grid 52. To compensate for the increase in luminance of the non-defective display pixels 40 immediately adjacent to the defective display pixel 50, the image processing circuitry may distribute a lower portion of the target luminance to non-defective display pixels 42 farther from the defective display pixel 50 compared to the non-defective display pixels 40 that are immediately adjacent to the defective display pixel 50. Similarly, if the electronic display 12 was arranged as the hexagonal grid 54, the compensation mask 56 may be used to conceal the defective display pixel 50 by offsetting nearby non-defective display pixels 48 (e.g., including non-defective pixels 40, 42) with a portion of the target luminance.
[0044] As illustrated by the square grid 52 of the electronic display 12, display pixels 40 that are immediately adjacent to the defective display pixel 50 may be distributed a portion of the target luminance that is greater than the portion of the target luminance distributed to other nearby display pixels 42. In other embodiments, nearby display pixels may receive similar portions of the target luminance despite relative distance from defective display pixel 50. For example, with the hexagonal grid 54 of the electronic display 12, display pixels 40 that are immediately adjacent to the defective display pixel 50 may be distributed a portion of the target luminance that is similar to the portion of the target luminance distributed to other nearby display pixels 42 due the hexagonal nature of the electronic display 12.
[0045] As discussed above, compensating for a point defect reduces the visual error stemming from a defective display pixel on the electronic display 12. Accordingly,
[0046] With the preceding in mind,
[0047] In some embodiments, when the processing circuitry receives the image data associated with an image from an image source, the image data may be in a gray level. As such, at block 114, the processing circuitry converts the gray level of the image data into a luminance domain. Converting the gray level of the image data into the luminance domain helps the processing circuitry identify the original luminance of the display pixel or a target luminance that would have been emitted by the display pixel had the display pixel not been defective.
[0048] To minimize the visibility of visual error resulting from the defective pixel when the image is displayed on the electronic display, at block 116, the processing circuitry distributes the target luminance of the defective display pixel to nearby non-defective display pixels within a distance from the from the defective display pixel according to a compensation mask. Distributing or offsetting the target luminance of the defective display pixel may involve the processing circuitry adding or subtracting a portion of the target luminance to the original amounts of light emitted by respective nearby non-defective display pixels of the electronic display. For example, a nearby non-defective display pixel may emit an amount of light that is greater than its original luminance by a portion of the target luminance. Further, another nearby non-defective display pixel may emit an amount of light that is lower than its original luminance by a portion of the target luminance. Non-defective display pixels that are closer to the defective display pixel may receive a greater portion of the target luminance compared to non-defective display pixels that are farther from the defective display pixel. For example, non-defective pixels immediately adjacent to the defective display pixel may receive a higher portion of the target luminance to conceal the defective display pixel. That is, as distance from the defective display pixel increases, a magnitude of the target luminance added to the nearby display pixels or subtracted from nearby display pixels decreases.
[0049] Further, it can be appreciated that after compensating for point defects, the visibility or visual error associated with the defective display pixels on the electronic display may be reduced by 50%, 80%, 90%, 100%, and the like. For example, after compensating for a point defect, a dead display pixel (e.g., fully dark display pixel) may be concealed by the compensating light that is emitted by the nearby non-defective display pixels. In some embodiments, the processing circuitry may select a particular compensation mask for distributing the target luminance based on determining that the visual error after applying the compensation mask to the image data may be lower than a threshold visual error.
[0050]
[0051] In addition to respective locations and luminance of the display pixels, the compensation mask 144 may also be selected based on of a pixel arrangement (e.g., square grid, hexagonal grid) of the electronic display 12. Using the compensation mask, the processing circuitry may determine a target luminance 148 of the defective display pixel 142. The target luminance 148 is indicative of the original luminance of the defective display pixel 142 had it not been defective. In order to distribute a portion 150 of the target luminance 148 to nearby non-defective pixels surrounding the defective display pixel 142 to compensate for the point defect, the processing circuitry may convert a gray level of the image data into a luminance domain (block 146). Converting the gray level of the pixel data into the luminance domain may help the processing circuitry identify the target luminance 148 of the defective display pixel had the display pixel not been defective. Further, converting to the luminance domain may help the processing circuitry distribute the portion 150 of the target luminance 148 to other nearby non-defective pixels. In some embodiments, after the point defect is compensated, the processing circuitry may convert the luminance domain of a respective display pixel (e.g., a nearby non-defective display pixel) to the gray level (block 152).
[0052] With the preceding in mind,
[0053] As discussed above, a processor may select a compensation mask based on a pixel arrangement of an electronic display and angular features of image content to be displayed. Accordingly,
[0054] At block 202, the processing circuitry may evaluate the image content for angular features. For example, the processing circuitry may identify that the image content is an image of mountain, where diagonal patterns are used to represent the mountain. At block 204, the processing circuitry may select a compensation mask that is suitable based on the angular features of the image content. For example, the processing circuitry may select a compensation mask suitable for honeycomb patterns if the image content includes honeycomb patterns.
[0055] In some embodiments, the processing circuitry may evaluate the image content for angular features based on the type of pixel arrangement. For example, if the pixel arrangement is a square grid, the processing circuitry may analyze the image content for angular features such as the diagonal patterns of the mountain in order to select a suitable compensation mask for correcting the point defect when the image of the mountain is displayed. For example, the processing circuitry may select a compensation mask that takes into account the diagonal features of the image content, the square grid of the display panel, and respective locations of the display pixels. Whereas if the image content includes horizontal pattern for display on the square grid of the display panel, the processing circuitry may select a different compensation mask that is suitable for the horizontal patterns. On a square grid, difference in angles between patterns (e.g., vertical patterns vs. horizontal patterns) may me more noticeable compared to other types of grids (e.g., hexagonal grid). As such, the processing circuitry may evaluate the type of patterns in the image content before selecting a compensation mask for a square grid.
[0056] In other embodiments, the processing circuitry may select a compensation mask without evaluating the image content for angular features. For example, if the pixel arrangement is a hexagonal grid and given the respective locations of display pixels remain constant, the processing circuitry may select a universal compensation mask despite varying angular features of the image content. That is, similar compensation masks may be applied for image content with diagonal patterns and image content with horizontal patterns on an electronic display with a hexagonal grid. Compared to square grids, hexagonal grids are prone to less noticeable visual errors despite changes in angular features. As such, in some embodiments, the processing circuitry may not evaluate the image content for angular features if the pixel arrangement is a hexagonal grid, thereby saving processing power.
[0057] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.
[0058] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).